Large relative bandwidth radar

Abstract

A method of detecting an object that may be coated with material for preventing or attenuating reflections of incident electromagnetic waves is disclosed in which pulses of electromagnetic wave energy are generated with a large relative bandwidth in the band from about 0.1 GHz to about 12.0 GHz. Preferably, the generated pulses have a pulse duration in the range from 0.1 nanosecond to 1 nanosecond. Those pulses of electromagnetic wave energy are directed toward the object and reflections of those pulses of electromagnetic wave energy which are incident on the object are detected by receiving apparatus. The method enables coated objects to be differentiated from uncoated objects.

I claim: 
     
       1. A method of detecting an object that may be coated with material for preventing or attenuating reflections of incident electromagnetic wave energy comprising the steps of (i) generating pulses of electromagnetic wave energy whose relative bandwidth is greater than 0.85 in the band from about 0.1 GHz to about 12.0 GHz,   (ii) directing those pulses of electromagnetic wave energy toward the object, and   (iii) detecting reflections from said object of those pulses of electromagnetic wave energy which are incident on the object.   
     
     
       2. The method according to claim 1 wherein in step (i) at least some of the pulses are generated with a pulse duration in the range from 1 to 0.1 nanosecond.   
     
     
       3. The method according to claim 2, wherein in step (ii) at least some of the pulses directed toward the object are carrier-free pulses.